The invention relates to a vacuum cleaner and, more particularly, to a vacuum cleaner including a coarse dirt separating chamber with dust filter and a fine dirt separating chamber including a cyclone.
Traditional vacuum cleaners utilize filters or so-called dust bags to filter dirt and other particles from air drawn by a motor. After utilizing the vacuum cleaner, the dust remains in the vacuum cleaner""s dust cylinder or dust bag. After multiple uses of the vacuum cleaner, the filter or dust bag must be cleaned or replaced. If the filter or dust bag is not cleaned or replaced, fine dust prevents the passage of air being drawn through the vacuum cleaner thus increasing the motor""s resistance and eventually causing the motor to bum out. Moreover, prior to cleaning or replacing the dust cylinder or dust bag, the vacuum cleaner""s ability to clean is continuously reduced as it is being used. Therefore, traditional vacuum cleaner designs have many disadvantages, including inconvenience to the user and degraded performance of the vacuum cleaner""s ability to clean.
Recently, cyclone type dust filters for use in vacuum cleaners have been proposed. For example, U.S. Pat. Nos. 5,893,938; 5,858,038; Des. 343,707; Des. 305,269; 4,373,228 and Des. 413,698 disclose vacuum cleaners with at least one cyclonic filter. In particular, U.S. Pat. No. 5,893,938 shows the use of a dust retaining wall at the base of a frustoconical cyclone type dust filter, and U.S. Pat. No. 5,858,038 sets forth preferred distances between the base of the dust box and the bottom of the frustoconical cone of less than 8 mm or between 30 mm and 70 mm. Other patents showing multiple cyclones for use in vacuum cleaners include U.S. Pat. Nos. 5,558,697; 5,160,356; 5,145,499; 5,090,976; 4,853,011; 4,853,008; 4,826,515; and 4,593,429. Moreover, U.S. Pat. Nos. 5,893,936; 5,853,440; 5,846,273; 5,078,761; and 4,643,748 show the use of a shroud within a cyclonic dust separation device to improve filtering capability, and U.S. Pat. No. 5,062,870 shows a shut off device for use in a cyclonic vacuum cleaner.
While many of these designs and constructions are satisfactory, it is desirable to provide continued improvements and alternative designs over existing and previously proposed designs to simplify assembly and improve filtering and dirt removal.
Generally speaking, in accordance with the invention, a vacuum cleaner including a coarse dust separating filter and fine dust separating cyclone is provided. The vacuum includes a container having an inlet for dirty air, an outlet for clean air, a coarse dust removing chamber and a fine dust removing chamber. A rotary cylinder is disposed in an upper part of the coarse dust chamber, a filtering tube is disposed within the rotary cylinder, and a rotary cone is disposed within the fine dust chamber. The container""s inlet is above the coarse dust chamber and the container""s outlet is above the rotary cone that is disposed within the fine dust chamber. The inlet also is disposed between the rotary cylinder and the filtering tube. A guide duct is provided that extends from an upper part of the filtering tube to an upper part of the rotary cone, and the guide duct is partially disposed within the rotary cone.
The container further includes a cover, a dust box and a barricade disposed between the cover and the dust box. The inlet, outlet and guide duct are in the cover, and the rotary cylinder and rotary cone are below the barricade. A sealing plate is located below the inlet and the guide duct, and the filtering tube is installed below the sealing plate.
A spiral guide blade is disposed around an upper part of the filtering tube and is adapted to cause air within the rotary cylinder to rotate. The filtering tube length (or depth) is the same as the length (or depth) of the rotary cylinder, and the filtering tube has a sealed bottom. The bottom of the filtering tube includes a bellmouthing to prevent dust from rising into the rotary cylinder from a lower portion of the coarse dust chamber.
The rotary cone has a partially open bottom that includes a cylindrical boss connected to the rotary cone by guide ribs at the cone opening. The cylindrical boss prevents dust from rising and entering into the rotary cone.
The filter includes a discharge air tube that extends from the outlet into the rotary cone, and the discharge air tube is coaxial with the rotary cone. The filter also includes an air volume protector that is adjacent to the guide duct to enable normal operation of the filter during various conditions.
A method of filtering dust in accordance with the invention is carried out by drawing air that contains fine and coarse dust into a first dust chamber having a cylinder and a filtering tube disposed within the cylinder. The drawn air and dust are supplied into the gap between the inner surface of the cylinder and the outer surface of the filtering tube. The air and dust are rotated in the first dust chamber so as to cause the coarse dust to travel outwardly away from the filtering tube and to cause the air and fine dust to travel inwardly towards and into the filtering tube. The air and fine dust within the filtering tube are supplied to a funnel-shaped cone disposed within a second dust chamber. The air and fine dust are rotated within the funnel-shaped cone to cause the fine dust to travel outwardly towards the inner surface of the cone and to cause air without dust to travel to the center of the cone. The air travelling at the center of the funnel-shaped cone then is supplied outside the second dust chamber as filtered air.
The coarse dust travelling away from the filtering tube falls below an open bottom of the cylinder and into a bottom portion of first dust chamber, which is irregularly shaped, which causes the rate of rotation of the coarse dust to decrease, and then collect on the bottom of the first dust chamber. The air and fine dust within the filtering tube are supplied into the funnel-shaped cone at a direction that is tangential to a curved portion of the funnel-shaped cone to facilitate rotation of the air and fine dust within the filtering tube.
Fine dust travelling outwardly towards the inner surface of the funnel-shaped cone falls through a gap adjacent to a cylindrical boss disposed at the bottom of the funnel-shaped cone and then into a bottom portion of the second dust chamber, and the falling fine dust is collected on the bottom of the second dust chamber.
Air travelling at the center of the funnel-shaped cone strikes the cylindrical boss on the bottom of the cone and is forced upwards through the center of the funnel-shaped cone towards the cone""s top, and the air at the top center of the funnel-shaped cone is supplied outside the second dust chamber as the filtered air.
In accordance with another embodiment of the invention, the cyclone dust filter for use with a vacuum cleaner includes a funnel-shaped cone with an opening at its smaller end and an inlet at the other end for receiving air tangentially along the inside of the cone. A cylindrical boss is disposed at the center of the cone""s opening and is held in place by at least one guide rib. The cylindrical boss is sized relative to the opening so that a gap exists around the cylindrical boss to allow dust travelling along the inner surface of the cone to travel past the cylindrical boss. Each guide rib is angled along a direction of air flow so as to not restrict the passage of dust through the gap.
The method of filtering dust is carried out by supplying air having dust tangentially along the inside of a funnel-shaped cone, rotating the air and dust within the cone to cause the dust to travel outwardly towards the inner surface of the cone and to cause air substantially without dust to travel along the center axis of the cone, deflecting the air travelling along the center axis by a deflecting structure which is disposed at the center of one end of the cone, supplying the deflected air outside the cone as filtered air, and allowing dust travelling along the inner surface of the cone to pass through a gap that is disposed between the deflecting structure and the surface of the cone. Substantially all of the dust travelling through the gap is collected and prevented from being supplied with any of the filtered air.
It is therefore an object of the invention to provide a separated cyclone dust filter for a vacuum cleaner that provides greater filtering ability over existing filtering designs.
It is a further object of the invention to provide a separated cyclone dust filter for a vacuum cleaner that does not increase air resistance through the filter as the filter accumulates dust and other dirt particles from air that is being drawn by the vacuum cleaner""s motor.
It is an additional object of the invention to provide a separated cyclone dust filter for a vacuum cleaner that incorporates the advantages of differently designed cyclone filters to provide extremely high separation efficiency as compared to existing designs.
Various other objects, advantages and features of the present invention will become readily apparent to those of ordinary skill in the art, and the novel features will be particularly pointed out in the appended claims.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.